1. Field of the Invention
This invention relates to a camera with a sight line detecting apparatus capable of detecting the position of a photographic line of sight.
2. Related Background Art
Japanese Laid-Open Patent Application No. 3-107932 discloses an apparatus for judging a watching position on the basis of a photographer's line of sight, storing a plurality of watching positions within a predetermined time by storing means, and calculating light metering information and range information by those watching positions.
Further, Japanese Laid-Open Patent Application No. 3-107933 discloses an apparatus for changing a weighting factor for each light metering area with a watching time, in addition to a watching position, being taken into account, and calculating light metering information.
In the apparatuses according to the prior art, however, when a range area and a light metering area are controlled by the watching point information within a predetermined time, they have been determined by the relation between the watching position and the length of the watching time without the lapse time of the watching point information being taken into account.
For example, when the oldest watching point information and the newest watching point information are entirely the same watching times, it is judged that the degrees of importance of those two kinds of watching point information are equal to each other. Actually, however, it is often the case that old watching point information in which time has elapsed is low in reliability.
Thus, it seems that in many cases, watching point information low in reliability remains and watching point information which seems to be high in reliability is erased. Accordingly, the information of AF and AE calculated on the basis of watching point information becomes low in reliability. This will prevent a photographer from performing photographing as he intends.
Further, it is conceivable for storing means storing watching point information therein to be saturated, and in that case, consideration must be given to watching point information to be erased when new watching point information is judged.
For example, where the watching time of the oldest watching point information stored in storing means is very long and the watching time of the second oldest watching point information is extremely short, reliability will become low unless which watching time should be preferentially erased is considered.